Means and method of encapsulating mechanically fastened belt splice for agricultural belt

ABSTRACT

A means and method for encapsulating a mechanically spliced belt, used in agricultural machinery, are disclosed. The encapsulating material protects the mechanical splice from exposure to environmental and operational conditions. The encapsulating material increases the cross-sectional modulus of the mechanical splice while maintaining geometric integrity of the fastening system, thereby increasing the operational life of the spliced belt.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This generally relates to mechanically fastened belt splices foragricultural machinery belts. The invention more particularly concernsmechanical splices which help to prolong the operational lives of thebelts, and to methods of making such splices.

2. Description of the Prior Art

Belting is used today in many types of agricultural machinery, e.g., haybalers. A popular type of hay baler which is marketed today employs aplurality of belts which are used to form the hay into round bales. Thistype of baler is known as a round hay baler. The belts which are used onthe round hay balers are typically in the order of 40 feet long and ofthe type described in commonly assigned U.S. Pat. Nos. 4,371,580 and4,900,609, which are incorporated herein by reference.

There are several factors which must be taken into consideration whendesigning belting for hay balers. One factor is that when a hay baler ismaking bales, the belts are subjected to heavy loads. These loads causethe belts to stretch, and the amount that a belt stretches under theload must remain within a certain tolerance; otherwise, the bale it ismaking will become too large, thereby interfering with proper baleroperation.

Manufacturers of hay balers have continued to increase the specificationfor the density of bales which a baler can produce. The amount ofloading to which the belts of a baler are thereby subjected isincreased, and hence the likelihood that a belt will stretch beyondtolerable limits for proper operation is increased. When a beltstretches beyond tolerable limits, the belt is generally removed andshortened. Shortening the belt is typically accomplished by trial anderror techniques, especially in the fields. Such trial and errortechniques are time consuming and can produce unsatisfactory results.

The two most common splices are vulcanized splices and mechanicalsplices. The underlying principle in vulcanized splicing is theestablishment of adhesion between the components of the two belt endsbeing joined together in the splices. The goal is to develop adhesion inthe splices equal to that in the original belt. In mechanical splices,the ends of the belt are connected by a mechanical device such as the"clipper splice" that is illustrated in FIG. 2.

Another factor to be considered in the design of belt splices is theability of the belt to flex in operation without damaging the splice. Inthat regard, a typical round hay baler employs a plurality of rollers onwhich the belts are installed. The position of the rollers is such thatthe belts are subjected to a substantial amount of flexing in travelingaround the rollers. Moreover, some of the rollers are positioned suchthat the belts must travel in an S-shape during operation. If a beltfails due to the flexing stress, the belt must be replaced to obtainproper operation of the baler. The typical failure point, particularlywhen mechanical splices are used, is at the point of splice.

Other factors when considering the type of splice to employ are cost andease of installation. Although vulcanized splices are generally moredurable than mechanical splices, they typically cost at least twice asmuch and they are much more difficult to install, particularly in thefield.

Belts used in agricultural applications are most commonly fastened withmechanical splices. The mechanical splices, however, tend to deterioraterapidly in operation and require substantial maintenance.

Belt slippage and mistracking are caused by a number of factors. In dryand dusty conditions, the dry crop and soil residue are deposited on thebelt surfaces and roller surfaces. The residue acts as a lubricantcausing both slippage and mistracking. In wet and slippery conditions,such as when baling wet hay or chopped silage, excess moisture also actsas a lubricant causing slippage and mistracking. Also, some crops, suchas silage, leave a sticky residue on the belts which causes cropmaterial to adhere to the belt surface. This causes the belts to reactunevenly at the rollers, again causing slippage and mistracking. Duringslippage and mistracking, the belts may contact fixed guides, the beltsmay roll over, and adjacent belts may rub together. These occurrencesdamage the belt edges and the ends of the mechanical fasteners.

Mechanical methods have been employed in an effort to overcome theslippage and crop material collection problems, but with minimal successand often to the detriment of the mechanical fastening system. One suchmethod has been to weld metal flighting, such as auger flighting, in aspiral configuration axially along a steel roller surface. The intent isfor the flighting to scrape off crop material collecting on the beltsurface. While the flighting does scrape the belt surface, it alsoscrapes the mechanical fastener. Many times the fastener is scraped fromthe belt.

Rigid and stationary belt dividers and guides are also employed toprevent mistracking. However, as the lateral edges of the belts contactthe guides, the ends of the mechanical fasteners become damaged.

The combination of crop conditions, built-in metal or rubber rollers,belt guides and other components that physically scrape the belt allresult in increased stresses and strains at the fastened area of thejoined belt ends. Mechanical fasteners transfer these stresses andstrains to the belt reinforcing fibers through the area of belt carcasspenetration and by the member of the fastener that actually penetratesthe belt carcass. There is a constant variable of stress and strain fromone point to another point along the cross-sectional plane of the beltand the fastener area. There is also a belt-to-belt difference inmultiple belted systems where the multiple belts are supported by thesame long rollers. This is the case in the round hay baler.

The continuous high frequency oscillations of the stress/strain loads onthe belt in operation are transferred to the points of the belt carcasspenetrated by the mechanical fastener. Also, as the belt and the joinedbelt ends flex about the roller surfaces in a serpentine manner, thismovement concentrates considerable stress/strain loads on the joinedbelt ends through the mechanical fastener due to the differences in beltsurface elongations under dynamic loading. This makes it inevitable thatthe fastened cross-sectional plane of the belt ends can experienceuneven stress/strain loads.

SUMMARY OF THE INVENTION

In accordance with the present invention, an encapsulated belt splice isprovided which exhibits superior dimensional stability characteristics;which is not subject to deterioration due to operational andenvironmental conditions; which is able to flex in operation withoutdestroying the mechanical fastener; and which is relatively inexpensiveto produce. The encapsulated splice is particularly useful for beltsthat are used in hay balers and other agricultural equipment and thatare spliced using mechanical fasteners.

In accordance with the present invention, the ends of a single- ormulti-ply belt are spliced with a mechanical fastener, and the twoopposed surfaces of the belt ends and the mechanical fastener arecovered with a protective material. The protective material increasesthe cross-sectional area, and thus the strength, of the splice andprotects the mechanical fastener from direct contact with the rollers orrigid belt scrapers.

In another embodiment of the invention, the protective material coversthe outside edges of the belt ends, at the splice, and thus covers thetwo ends of the mechanical fastener. The protective material helps toprevent both the corners of the belt ends and the ends of the mechanicalfastener from contacting either the rigid belt guides or adjacent belts.

In yet another embodiment of the present invention, the protectivematerial bonds to the ends of the belt and to the mechanical fastenerbut does not bond to the shear connector, or clad pin, that is insertedthrough the mechanical fastener. This enables the protective material toprotect the belt splice while enabling the splice to be more flexible asit passes over the rollers.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view of a three-ply belting which is typicalof belting commonly used in agricultural applications.

FIGS. 2 is a perspective view of belting which illustrates a type ofmechanical splice commonly used on belting in agricultural applications.

FIG. 3 is a perspective view of mechanically-spliced belting in whichthe corners of the ends of the spliced belts are removed.

FIG. 4 is a perspective view partially exploded of an encapsulated beltsplice in accordance with the present invention.

FIG. 5 is a perspective view of an encapsulated belt splice inaccordance with the present invention.

FIG. 6 is a cross-sectional view of an encapsulated belt splice inaccordance with the present invention.

DESCRIPTION OF A PREFERRED EMBODIMENT

Before a preferred embodiment of the invention is explained in detail,it is to be understood that the invention is not limited in itsapplication to the details of construction and the arrangement of thecomponents set forth in the following description or illustrated in thedrawings. The invention is capable of other embodiments and of beingpracticed or carried out in various ways. Also, it should be understoodthat the phraseology and terminology used herein is for the purpose ofdescription and should not be regarded as limiting.

With reference to FIG. 1, the belting 100 includes one or more layers ofply material 102 interposed with layers of inner rubber skim 104. Thebelting also has two outer rubber skims 106, which provide opposedsurfaces 110.

With reference to FIG. 2, the belting comprises two opposed lateraledges 200 and two ends 202. The ends of the belting 202 may be splicedtogether by using known techniques. One such technique is illustrated inFIG. 2. It is known as the so-called "clipper lace" splice technique.With this technique, a plurality of metal eyelets or hooks 204 areconnected in each end of the belting and a rod 206, or other suitableshear connector or clad pin, is passed through the eyelets. In oneembodiment of the present invention, the corners 208 of the ends of thebelting are notched to form a fillet between the ends of the belting 202and the lateral edges 200, as illustrated in FIG. 3.

With reference to FIG. 4 and 6, in one embodiment of the presentinvention, the outer rubber skims 106 are skived, or removed, a distance300 back from the ends of the belting 202. The skiving is performed suchthat the outer surfaces 302 of the outermost ply layers 102 are notdamaged. The exposed surfaces 302 are cleaned with a nonresidue solvent,and a bonding cement of the type used to bond vulcanized rubber to a rawor unvulcanized gum is then applied to the exposed surfaces. After thecement is dry, a mechanical fastener of the type illustrated in FIGS. 2and 3 that has been cleaned and coated with an adhesion agent, such asLord Corp., Chemlok 205, is installed on the prepared belt ends.

A layer of bonding gum 304 is applied parallel to the splice such thatthe two prepared exposed surfaces and the two lateral edges of the twobelt ends are covered by the gum. Next, a layer of reinforcing material306, such as nylon netting or fabric, is applied such that it surroundsthe previous layer of bonding gum. Finally, a layer of outsideprotective material 308, similar in composition to the outer rubberskims 106, is placed such that it surrounds the reinforcing material andgum layers. The protective material is then vulcanized or otherwiseproperly cured to form a protective sealant.

In another embodiment of the present invention, the clad pin 206 istreated with a lubricant or metallic bushing material such that neitherthe bonding gum 304 nor the protective material 308 adheres to the pin.Thus, after curing, the pin is free to rotate within the splice.

What is claimed is:
 1. Machinery belting comprising:a length of belthaving at least one ply layer and mechanical fasteners splicing oppositeends of the belt; and a band of protective material bonded, along thesplice, to the mechanical fasteners and the belt so as to seal andencapsulate the splice.
 2. The belting of claim 1 in which theprotective material comprises a plastic.
 3. The belting of claim 1 inwhich the protective material comprises a thermoplastic.
 4. The beltingof claim 1 in which the protective material comprises a thermosettingpolymer.
 5. The belting of claim 4 in which the thermosetting polymercomprises natural or synthetic rubber.
 6. A conveyor or drive beltingcomprising:a belt having two ends, two opposed surfaces, two lateraledges and at least one layer of ply material; mechanical fastenersattached to the two ends and coupled together to form a mechanicalsplice; and a band of protective material extending laterally around thebelt and covering the splice, said protective material cured and bondedto the belt surfaces, the lateral edges and the mechanical fasteners toencapsulate the splice.
 7. The belting of claim 6 which furthercomprises a shear connector coupling the mechanical fasteners.
 8. Thebelting of claim 7 in which the shear connector is free to rotaterelative to the coupled mechanical fasteners.
 9. A mechanically splicedbelt comprising:at least one layer of ply material and a first layer ofcover over the layer of ply material; and a layer of protective materialsupplanting the cover to a depth approaching the ply material andextending across the splice and laterally around the belt, including themechanical splice, to encapsulate the splice, said protective materialbeing bonded to the belt including the ply material.